The long arm of politics reaches deep inside agencies in the federal government, sometimes pulling the strings for officials whose decisions have far-reaching consequences.

Lester M. Crawford's decision on one issue at the Food and Drug Administration shows that the reach extends into science-based agencies that should be better insulated from partisan politics. Mr. Crawford, the FDA chief, postponed indefinitely on Friday a ruling on whether to allow over-the-counter sales of "Plan B," the morning-after pill. Intended for use when Plan A (contraception) fails or is skipped, this medicine can prevent unwanted pregnancy if taken within three days of unprotected sexual intercourse.

Plan B has been available by prescription only, and there is an urgent need for easier and wider access to the drug. Some estimates suggest that nonprescription sales would reduce the number of abortions by 800,000 annually.

The FDA's foot-dragging on allowing over-the-counter sales led to the resignation yesterday of one of its top-ranking officials. Susan Wood, director of the FDA's Office of Women's Health, said in an e-mail to colleagues, "I can no longer serve as staff when scientific and clinical evidence, fully evaluated and recommended for approval by the professional staff here, has been overruled."

For years abortion opponents and religious conservatives have flooded the White House with objections to easy access to the morning-after pill. They regard it as an abortion medicine, rather than emergency contraception, and fear it may increase promiscuity among teens.

The FDA's scientific advisers concluded in 2003 that Plan B is safe enough to be sold without a prescription, and the FDA staff agreed. FDA managers, however, rejected the advice -- supposedly because younger teenagers might not understand instructions for taking the pill.

The drug's manufacturer then asked for an OK to sell Plan B over-the-counter only to older teens. The FDA's scientific staff backed the idea of limiting sales to women age 17 and over.

While acknowledging that science supports the approach, Mr. Crawford now claims that the FDA needs months more to consider the issue. One big concern, he said, is figuring out how to keep younger teenagers from buying the drug. Here's an idea: How about having store clerks check the buyer's ID, as they do for tobacco and alcohol?

Mr. Crawford's other excuses for stringing out this process sound just as lame, and reek of political meddling in science. Susan Wood's resignation bears that out.

Public confidence in the FDA already is shaky, amid criticism that it ignored scientific warnings about the heart-attack side effects of the painkiller Vioxx and the use of antidepressants in children. The FDA's Plan A should be to confront concerns that politics trumps science in its executive suite, and stop stalling on Plan B.